A carton full of books rests on a wooden floor. The normal force the floor exerts on the carton is 239 Newton.
(a) You push horizontally on the carton with a force of 126 Newton, but it refuses to budge. Explain what can you say about the coefficient of static friction between the carton and the floor?
(b) If you must push horizontally on the carton with a force of at least 135 Newton to start it sliding, evaluate what is the coefficient of static friction?
(c) Once the carton is sliding, you only have to push with a force of113 Newton to keep it sliding. Calculate what is the coefficient of kinetic friction?